(1) Field of the Invention
This invention relates to article surveillance systems and, more particularly, to an electronic article surveillance (EAS) system having multiple article surveillance and detection systems combined.
(2) Description of Related Art
In general, several types of EAS systems exist that operate on different physics and technology principles, each of which offer various advantages and disadvantages. Non-limiting, non-exhaustive list of examples of known individual EAS systems include electromagnetic EAS systems, Radio Frequency (RF) EAS systems, and acousto-magnetic EAS systems. Regrettably, most savvy shoplifters are keenly aware of the disadvantages of each individual system, exploiting individual system weaknesses to circumvent and overcome the overall surveillance capabilities. For example, it is well known that most systems can be circumvented by placing an article with an attached EAS tag in a bag lined with aluminum foil, with the bag (also known as booster bag) acting as Faraday shield or cage to isolate the EAS tag from the antennas system of EAS systems, rendering the EAS tag useless. Other well-known methods of circumventing EAS systems include jamming transmission signals from an EAS system transmitter.
Accordingly, in light of the current state of the art and the drawbacks to current individual EAS systems exemplarily listed above, a need exists for an EAS system that includes and combines multiple individual electronic article surveillance systems, resulting in a robust surveillance system that overcomes the weakness of each individual system if implemented separately, synergically improving the overall surveillance capability.